This research has two major thrusts. (1) One is to follow a large sample of children as they go through their 7th, 8th and 9th years of schooling, the early years of adolescence. These children, who comprise a stratified random sample of Baltimore students, have already been continuously followed over their first six years of school. Information has been secured directly from them, their parents and their teachers starting from the time they began first grade. (2) The other thrust is to analyze the information about these children that is so far available in order to shed light on how their cognitive and affective development responds to social structural factors (minority/majority status, gender, family configuration, socioeconomic background, school climate) and to their immediate social context (parents, teachers, peers). The general analytic strategy employs structural equation models to elucidate the processes by which the various social factors affect development. Considerable analysis of cognitive development over first and second grades is already available (papers appended). Particular attention in future analyses would be paid to (a) the interdependences between cognitive and affective development; (b) how children negotiate transitions like school entry or school change; (c) how developmental processes of minority and majority youngsters differ, (if they do); (d) the extent to which continuity or discontinuity characterizes the developmental trajectories of this sample of "typical" urban children; (e) how children develop an academic self-image and sense of control, and especially how school performance shapes these aspects of personal development. The theoretical context for this work derives from life course ideas, sociological research on status attainment, and cognitive themes of child development. Understanding the social factors that shape "normal" development is fundamental to providing environments in which all children can develop to their full potential. Encouraging full development in childhood benefits both mental and physical health over the long run.